Hipparcos-2 Intermediate Astrometry Data

Reference: van Leeuwen, F. 2007, Hipparcos, the New Reduction of the
Raw Data: Astrophysics and Space Science Library, Volume 350. ISBN
978-1-4020-6341-1. Springer Science+Business Media B.V., 2007.
doi:10.1007/978-1-4020-6342-8

These data are a verbatim reproduction of the Intermediate Astrometry
Data (IAD) of the 2007 Hipparcos re-reduction. They were taken from
the DVD that accompanies the book by van Leeuwen (2007). The residuals
are relative to the best-fit astrometric solution described by the
astrometric catalogue, taking into account higher order terms of the
solution (7p, 9p, vim, ...). To ensure consistency, the IAD must be
used together with the astrometric parameters taken from the same
source, i.e., the catalogues served on the DVD.

The IAD consists of two parts:

a) Table G.8 in van Leeuwen (2007): The "basic" abscissa residuals and
formal errors for each field transit of a given source, corresponding
to the published solution. These data were given as ascii files on the
DVD. The data was parsed according to the data model given in the book
and split into two tables: resrec_header contains the headers (one row
per source) and resrec_data contains the residual data records
(resrec_header.Nobs records per source).

b) Table G.9 in van Leeuwen (2007): The full field-transit information
including all details used to derive the final catalogue. The data
correspond to the one-but-last iteration of the astrometric
solution. It was given in binary files on the DVD. The data was
decoded according to the data model given in the book and split into
two tables: absrec_header contains the headers (one row per source)
and absrec_data contains the transit data records (absrec_header.NObs
records per source).

Refer to Section G.2.2 in the book for more details.

ESA Hipparcos and Tycho Legacy Archive team

3 June 2021